The monitoring of automobile performance, particularly gas consumption, has been heretofore approached only from a very perfunctory basis. The typical fuel gauge, when monitored carefully, shows an extremely non-linear relationship between needle movement and fuel use. Inaccuracies occur particularly in the critical low fuel range of 5-10% or more. In the past, because of this limitation, some luxury automobiles have had a feature of an audible and flashing light alarm to indicate when a low fuel condition exists. These systems, which are added to the existing fuel level, have no greater accuracy than the fuel level monitor itself.
In recent years, with the availability of computer techniques and reliable and less expensive computer equipment, a number of systems have been developed for providing somewhat more definitive vehicle performance information. Representative of patents showing such systems are:
U.S. Pat. No. 3,927,305 issued to F. Grehl on 12/16/1975.
Other patents have issued on engine or static engine analysis equipment designed for either factory or garage use but not involving any vehicle while on the road. Such patents are represented by the following:
U.S. Pat. Nos. 3,815,411 R. S. Emerson: 6/11/1974 PA1 3,777,559 L. V. Rennick: 12/11/1973 PA1 3,630,076 J. E. Staudt: 12/28/1971. PA1 U.S. Pat. Nos. 3,958,107 A. C. Edelson et al 5/18/1976 PA1 3,750,465 J. S. Howell et al 8/7/1973 PA1 3,721,120 J. S. Howell et al 3/20/1973. PA1 U.S. Pat. Nos. 3,952,829 L. O. Gray: 4/27/1976 PA1 3,878,363 R. G. Terwilliger 4/15/1975. PA1 (a) miles per hour; PA1 (b) miles per gallon; and PA1 (c) miles to empty tank.
More elaborate engine performance systems designed particularly for aircraft or gas turbine engines are disclosed in the following patents:
Speed control systems involving monitoring of the actual speed and comparing it with the desired speed are shown in a number of patents as represented by:
None of the above recognize the need for actual vehicle performance data including miles-to-end-of-tank with the data actually calibrated to the vehicle.
A non-calibrated digital vehicle performance system is shown in U.S. Pat. No. 3,927,305 to F. Gruhl, issued 12/16/1975, and I understand microprocessors per se have been proposed and possibly employed in vehicles for performance monitoring.